Polarization Characteristics of High Valence Ion Doped Bismuth Lanthanum Titanate Ceramics

Abstract

Bi_3.25La_0.75Ti_3−3x Nb_3x O₁₂ (BLTN) and Bi_3.25La_0.75Ti_3−3x V_3x O₁₂ (BLTV) ceramics (x = 0, 0.01, 0.03, 0.05, 0.07 and 0.1) were prepared by a solid state reaction method. For all BLTN and BLTV compositions, bismuth-layered perovskite structures were confirmed using X-ray diffraction. The remanent polarization increases and reaches to the maximum value at x = 0.05 for BLTN and at x = 0.01–0.03 for BLTV ceramics. With increasing doping concentrations, the Curie temperature of BLTV ceramics increased while that of BLTN ceramics decreased. For the substitutions of high-valence Nb^{5 +} and V^{5 +} ion for Ti^{4 +} ion, effects of ion doping on dielectric and ferroelectric properties were investigated.

Keywords:

• Bi₄Ti₃O₁₂ (BIT)
• FRAM
• ferroelectric
• BLT
• Bi-layered perovskite

ACKNOWLEDGEMENTS

This work was supported by Korean Science & Engineering Fundation (KOSEF) through Grant No. R08-2004-000-10557-0.